1112 STACK SAMPLING
disulfide (CS 2 ) emissions from stationary sources, such as
tail gas control units for sulfur recovery plants. Any gas chro-
matographic system with a flame photometric detector (FDP)
shown to be capable of resolving the compounds of interest
and meeting the specifications in the method is acceptable.
A stainless steel or glass probe equipped with a particu-
late filter is used to extract stack gas continually. Condensed
water, carbon dioxide, carbon monoxide, and elemental
sulfur can interfere with the analysis. The analyst must
show that these substances will not affect the determination.
A dilution system is usually employed to reduce the effects
of the CO and CO 2. The water condensation problem is min-
imized by heating the sampling lines by the dilution system.
Heating the sampling lines will help to prevent buildup of
sulfur in the lines. However, the probe and sampling lines
should be inspected after each run and cleaned if necessary.
If the probe is observed to be clogged during a run, the run
must be repeated. The performance tests for calibration pre-
cision and calibration drift must fall within the stated limits.
Calibration procedures and leak checks in the method must
be followed. Aliquots of the diluted, heated sample stream
are withdrawn periodically and injected directly into the
GC-FPD for analysis. A sample run consists of a minimum
of 16 injections over a period of not less than three hours or
more than six hours.
The EPA Test Method 15 write-up contains performance
specifications, instructions for sampling and calibration
along with a list of references. The manual for the gas chro-
matograph should be consulted before using this equipment.
As with all of these methods, testing should be performed
only by personnel trained and experienced with the sampling
procedure and gas chromatography required by this method.Test Method 15ATest Method 15A is used to determine total reduced sulfur
emissions from sulfur recovery plants in petroleum refineries.
An integrated gas sample is extracted from the stack.
A measured amount of air is added to the stack gas during
sampling. This oxygen enriched mixture is passed through
an electrically heated quartz tube at 1100 50°C, and the
sulfur compounds are oxidized to sulfur dioxide (SO 2 ). The
remainder of the train is identical to that used for Method 6.
The SO 2 collected in the hydrogen peroxide solution is ana-
lyzed using the barium-thorin titration technique.
The EPA Test Method 15A write-up contains detailed
instructions, along with a list of references. It should be
read in detail before the Method is attempted. As with all of
these methods, testing should be performed only by trained
and experienced personnel using equipment and materials
designed for this purpose.Test Method 16Test Method 16 is a semi-continuous method for the determi-
nation of total reduced sulfur (TRS) emissions from station-
ary sources such as recovery furnaces, lime kilns, and smelt
dissolving tanks at kraft pulp mills. Total reduced sulfurincludes hydrogen sulfide (H 2 S), methyl mercaptan (MeSH),
dimethyl sulfide (DMS), and dimethyl disulfide (DMDS).
These compounds are separated by gas chromatography and
measured with a flame photometric detector.
The interferences, performance specifications, sampling
and analysis procedures are very similar to those of Test
Method 15.
The EPA Test Method 16 write-up contains instructions,
along with a list of references. It should be read in detail
before the Method is attempted. As with all of these meth-
ods, testing should be performed only by trained and expe-
rienced personnel using equipment and materials designed
for this purpose.Test Method 16AThis method is applicable to the determination of total
reduced sulfur (TRS) emissions including hydrogen sulfide
(H 2 S), carbonyl sulfide (COS), dimethyl sulfide (DMS), and
dimethyl disulfide (DMDS).
The sampling train for Method 16A is similar to the
Method 15A train except that there is a citric acid scrubber
before the oxidation tube to remove sulfur dioxide. Because
the sources that would use this method have sufficient
oxygen in their exhausts, additional air is not added before
the oxidation step. The oxidized sulfur compounds are col-
lected and analyzed as in Method 6. Sampling runs are either
three hours, or three samples collected for one hour each.
This provides data that are comparable with Method 16,
which requires runs to be from three to six hours.
A system performance check is done to validate the sam-
pling train components and procedure before the test and to
validate the results after the test. Audit samples for Method 6
are used with this method.
The EPA Test Method 16A write-up contains instruc-
tions, along with a list of references. It should be read in
detail before the Method is attempted. As with all of these
methods, testing should be performed only by trained and
experienced personnel using equipment and materials
designed for this purpose.Test Method 16BThis method is applicable to the determination of total
reduced sulfur (TRS) emissions, i.e., hydrogen sulfide
(H 2 S), carbonyl sulfide (COS), dimethyl sulfide (DMS), and
dimethyl disulfide (DMDS).
The sampling and analytical equipment and procedures
train for Test Method 16B is similar to those used in Method
16A, except that gas chromatography is used to determine
the SO 2 formed by the oxidation of the TRS, instead of the
Method 6 procedure. There must be at least 1% oxygen in
the stack gas for the oxidation procedure to work properly.
As with Method 16, 16 injections are required per run over a
period of not less than three hours nor more than six.
A system performance check is done to validate the sam-
pling train components and procedure before the test and to
validate the results after the test.C019_003_r03.indd 1112C019_003_r03.indd 1112 11/18/2005 11:07:16 AM11/18/2005 11:07:16 AM